Abstract
Objective:
Congenital heart diseases (CHD) are often associated with thymus development disorders and immune dysfunctions. However, the features of thymocyte differentiation in cyanotic and acyanotic CHD remain unknown.
Materials and Methods:
We have analyzed the main thymocyte subsets depending on CD4 and CD8 co-expression, and the number of natural regulatory T-cells (nTreg) and invariant natural killer T-cells (iNKT) precursors in the co-cultures of thymocytes with thymic plasmacytoid (p) dendritic cells (DCs) in vitro, isolated from the thymus of children with acyanotic (without hypoxia) and cyanotic (with severe hypoxia) CHD.
Results:
In the thymocyte co-cultures with pDCs in cyanotic CHD, compared to acyanotic CHD, a decreased number of thymocytes expressing αβ chains of the T-cell receptor with CD4 and CD8 lower levels (CD4loCD8loαβTCR+), but the increased numbers of CD4hiCD8-/loαβTCR+ cells were detected. The numbers of CD4CD8αβTCR+, CD4hiCD8hiαβTCR+, CD4-/loCD8hiαβTCR+ cells did not differ between cyanotic or acyanotic CHD. In cyanotic CHD in the thymocyte co-cultures with pDCs, the decreased number of CD4+CD25+FOXP3+ cells, nTreg precursors, was detected in comparison with acyanotic CHD. In cyanotic CHD, the number of CD3hiVα24Jα18+ cells, iNKT precursors, in the thymocyte co-cultures with pDCs did not differ in comparison with acyanotic CHD. Hypoxia in cyanotic CHD increased the resistance to apoptosis of thymocytes in co-cultures with pDCs in comparison with acyanotic CHD.
Conclusion:
Thus, hypoxia affected the main CD4+ and CD8+ αβTCR T-cell subsets and the number of CD4+CD25+FOXP3+ cells in the thymocyte co-cultures with pDCs isolated from thymus of children with CHD.
Keywords:
Congenital heart diseases, hypoxia, thymocytes, iNKT, nTreg, pDCsVOLUME
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ISSUE
Correspondence
Received
Accepted
Published
Suggested Citation
DOI
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